The objective of the present study was to evaluate the effect of batroxobin agents on perioperative hemorrhage in thoracic surgery.We systematically searched Cochrane Library, Pubmed, EMBASE and the China Biological Medicine CD-ROM Databases up to August 2007. Reference lists of all included studies and of reviews related to the topic of the present systematic review were manually searched. Two reviewers independently identified the eligible studies, assessed their methodological quality and extracted data. Results of relevant outcomes were pooled together whenever possible, using RevMan software.Five randomized controlled trials involving 678 patients were included. Three trials were for pneumonectomy and two for cardiac surgery with cardiopulmonary bypass. The quality of the identified studies was generally poor. All the trials claimed randomized allocation, but allocation concealment was unclear. Blinding was not mentioned. Two trials found that batroxobin agents decreased intraoperative blood loss for pneumonectomy. Mean differences between the batroxobin agents group and the no-treatment group were -182.20 ml [95% confidence interval (CI), -207.48 to -156.92] and -131.32 ml (95% CI, -142.95 to -119.69), respectively, for these two trials. All included trials reported less drainage volume favoring the batroxobin agents group. Mean differences at different time points after operation ranged from -15 ml (95% CI, -31.77 to 1.77) to -150.60 ml (95% CI, -179.26 to -121.94). Although most of the differences between the batroxobin agents group and the no treatment group were statistically significant, clinical value was limited.There is not enough evidence supporting any benefit of batroxobin agents for hemorrhage during thoracic surgery.